1. Field of the Invention
The present invention relates to an airbag for head-protecting airbag device which is normally folded and housed in an upper edge of windows in the interior of vehicle including a front pillar sloping down forward, and deployable to cover the interior of the windows upon inflow of inflation gas.
2. Description of Related Art
In the prior art, Japanese Patent Laid-Open No. 2000-335351 is illustrative of an airbag for head-protecting airbag device which includes a plurality of protection portions juxtaposed along the vehicle's front-rear direction as deployed.
In this airbag, both of a front protection portion arranged forward and a rear protection portion arranged rearward include a plurality of horizontal inflatable chambers arranged along the front-rear direction of the vehicle, and the horizontal chambers are juxtaposed along the vertical direction.
It is usually desired regarding this kind of airbag that a tension along the front-rear direction is exerted in the lower edge of the inflated airbag as well as that the completely inflated airbag covers the vehicle's inner side of windows to protect vehicle occupants.
In the airbag for head-protecting airbag device in the prior art, however, since all the protection portions are constituted by horizontal chambers, the completely inflated airbag does not shrink to reduce its longitudinal length. Accordingly, a great tension along the front-rear direction is hardly exerted in the lower edge of the airbag completely inflated although the airbag is able to secure a wide protection area in the front-rear direction. Especially, a front part of the front protection portion for covering a window at the side of a front seat is folded and housed in a front pillar which is extended from a roof side rail obliquely down and forward. The part attached to and housed in the front pillar is secured to the body in the front pillar at a plurality of positions arranged along the front-rear direction in the upper edge. Accordingly, when the part develops downward, the part occupies a great part of the length of the airbag lower edge in the front-rear direction. Consequently, a tension along the front-rear direction is hardly exerted in the lower edge of the airbag completely inflated.